Covalent Photochemical Functionalization of Amorphous Carbon Thin Films for Integrated Real-Time Biosensing

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• 作者：Bin Sun ; Paula E. Colavita ; Heesuk Kim ; Matthew Lockett ; Matthew S. Marcus ; Lloyd M. Smith ; Robert J. Hamers
• 刊名：Langmuir
• 出版年：2006
• 出版时间：November 7, 2006
• 年：2006
• 卷：22
• 期：23
• 页码：9598 - 9605
• 全文大小：196K
• 年卷期：v.22,no.23(November 7, 2006)
• ISSN：1520-5827

文摘

Recent studies have demonstrated that carbon, in the form of diamond, can be functionalized with molecular and/orbiomolecular species to yield interfaces exhibiting extremely high stability and selectivity in binding to target biomoleculesin solution. However, diamond and most other crystalline forms of carbon involve high-temperature deposition orprocessing steps that restrict their ability to be integrated with other materials. Here, we demonstrate that photochemicalfunctionalization of amorphous carbon films followed by covalent immobilization of DNA yields highly stable surfaceswith excellent biomolecular recognition properties that can be used for real-time biological detection. Carbon filmsdeposited onto substrates at 300 K were functionalized with organic alkenes bearing protected amine groups andcharacterized using X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy. The functionalizedcarbon surfaces were covalently linked to DNA oligonucleotides. Measurements show very high selectivity for bindingto the complementary sequence, and a high density of hybridizing DNA molecules. Samples repeatedly hybridizedand denatured 25 times showed no significant degradation. The ability to use amorphous carbon films as a basis forreal-time biosensing is demonstrated by coating quartz crystal microbalance (QCM) crystals with a thin carbon filmand using this for covalent modification with DNA. Measurements of the resonance frequency show the ability todetect DNA hybridization in real time with a detection limit of <3% of a monolayer, with a high degree of reversibility.These results demonstrate that functionalized films of amorphous carbon can be used as a chemically stable platformfor integrated biosensing using only room-temperature processing steps.